What a vivid realization of the deafening roar of the water, that the gun, although fired directly over his head, and almost within arm’s-length, still failed to give him the slightest report. Little Rifle now showed a keenness of perception and a fertility of resources which in reality was nothing short of the wonderful. As he stood with his rifle held to his shoulder, and his finger pressing the trigger, his view of the Indian bursting through the sheet of water, like the athlete of the hippodrome leaping through the ring of paper, was sharply distinct, although but for a passing moment of time. The expression upon the face of the Blackfoot was that of surprise at seeing the two lads before him. He did not expect to see them--was not looking for them, and the red-skins who remained upon the outside were not aware of their being there. This, as all will see, was a great point in favor of the lads, if the deception could be continued; but there was the imminent danger that the rest of the Blackfeet, waiting in vain for the return of their comrade, would discover the truth. In such a case, a desperate fight, with the certainty of a fatal result upon the part of the lads, was sure to follow. Comprehending the nature of the Indian, with its childish credulity and superstition, Little Rifle determined to appeal to this weakness. The Blackfeet believe that the waterfalls of their country are haunted by spirits, and knowing of the existence of the cavern in the rear of this, they could not but look upon the act of their companion as one of daring intrepidity. The young trapper touched the arm of Harry, and motioned for him to draw back out of the way, while he crept forward until his eyes were at a point where he could see the Indians without showing himself. He waited only long enough to see that fully a half-dozen were clustered upon the rocks, where he suspected they were discussing the action of their companion. Little Rifle then pushed his gun forward, and pulled the trigger. It was not aimed at the group, for he had no desire to injure any of them, unless compelled to do so in self-defense, but through the gauzy vail every one of them must have caught sight of the sheet of fire, without hearing any thing of the report. This was enough, and they vanished from the spot as suddenly as if the ground had opened and swallowed them, not one being visible a dozen seconds afterward. This was also a huge step forward upon the part of the boys, but there remained still the difficult necessity of getting out of their uncomfortable quarters, and making their way back to the cabin of old Ruff Robsart. If the Blackfeet had left the rock, it was hardly probable that they had left the neighborhood, and the moment the boys should show themselves, they would be in for it again.